# -*- coding: utf-8 -*-

#
# peerscape.http.controllers.delete
#
# Copyright 2008 Helsinki Institute for Information Technology
# and the authors.
#
# Authors:
#       Konrad Markus <konrad.markus@hiit.fi>
#

# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation files
# (the "Software"), to deal in the Software without restriction,
# including without limitation the rights to use, copy, modify, merge,
# publish, distribute, sublicense, and/or sell copies of the Software,
# and to permit persons to whom the Software is furnished to do so,
# subject to the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

from __future__ import with_statement

import logging
import urllib

from webob import Response
from webob.exc import HTTPForbidden, HTTPBadRequest, HTTPOk

from peerscape.lib import json
from peerscape.http.controllers import BaseController

class Delete(BaseController):
    def index(self, req):
        if req.method == 'POST':
            db = req.environ['peerscape.db']
            iid = req.urlvars.get('peerscape.hexlabel')
            path = urllib.unquote(req.urlvars.get('peerscape.path'))

            if not iid or not path:
                return HTTPBadRequest()

            dom_cipher = None
            if req.POST.get('auto_crypt'):
                try:
                    dom_cipher = db.get_group_cipher(iid)
                except LookupError:
                    assert dom_cipher == None
                    pass

            # delete value
            path = '/'+path
            if req.POST.get('insertpath'):
                # insertpath handling; assumes we are working with json values
                insertpath = req.POST['insertpath']

                # strip out the action from the beginning of the insertpath
                # action an be one of: append, prepend [for list targets] or set
                action = insertpath[0:4]

                # only $set is allowed for delete
                if action in ['$set']:
                    insertpath = insertpath[4:]
                else:
                    return HTTPBadRequest()

                # get the current json value
                cur_value = db.get_json(iid, path)

                if cur_value == None:
                    # insertpath cannot work on a non-existent value
                    return HTTPBadRequest()

                try:
                    # evaluate the path against the cur value
                    (stack, cur, oB) = ([], '', False)
                    for c in insertpath:
                        if c == '[':
                            oB = True
                            if cur:
                                stack.append(cur)
                                cur = ''

                        elif c == ']':
                            if cur:
                                # only integer indices for lists can be used in square bracket notation
                                stack.append(int(cur))
                                cur = ''
                            oB = False

                        elif c == '.':
                            if cur:
                                stack.append(cur)
                                cur = ''
                        else:
                            cur = cur + c

                    # don't forget the last element if any
                    if cur:
                        stack.append(cur)

                    # reserve the last element of a $set stack
                    if action == '$set':
                        last = stack.pop()

                    # step through structure
                    stackp = cur_value
                    for e in stack:
                        stackp = stackp[e]

                    # remove the item
                    del stackp[last]

                    # set the value
                    try:
                        db.put_json(iid, path, cur_value, cipher=dom_cipher)
                    except:
                        logging.exception("delete: error.")
                        return HTTPForbidden()
                except:
                    logging.exception("delete: error.")
                    return HTTPBadRequest()
            else:
                try:
                    db.delete(iid, path)
                except:
                    logging.exception("delete: error.")
                    return HTTPForbidden()
            
            # form a success response, including any jsonp
            res = HTTPOk()
            if req.POST.has_key('jsonp'):
                res.body = '%s("%s")' % (req.POST['jsonp'], path)
            else:
                res.body = '("%s")' % path
            return res
        else:
            return HTTPBadRequest()

